The present invention generally relates to a printing apparatus, and more particularly to a printing apparatus having one or more paper supply trays, which printing apparatus can perform bidirectional communication with a plurality of user terminals.
A printing apparatus, for example, disclosed in Japanese Patent Publication No. 3-12014 has a plurality of paper-supplying means so that one paper-supplying tray being used can be automatically changed to another paper-supplying tray when recording papers are out. That is, in this apparatus, when recording papers stored in one of paper-supplying trays are out, another tray is selected to continue a paper-supplying operation. The tray is selected from among paper-supplying trays which were previously assigned.
A recording apparatus disclosed in Japanese Laid-Open Patent Application No. 60-242146 has a plurality of paper cassettes, each storing different sizes of recording papers. In this recording apparatus, when a user selects a size of recording paper to be used, the paper cassette in which the recording paper is of the selected size is automatically used.
Additionally, Japanese Laid-Open Patent Application No. 2-182636 discloses an image-forming apparatus which automatically changes a paper-supplying tray when the recording papers in one paper-supplying tray being used are out. The selection of the paper-supplying tray is performed on the basis of a priority order given to each paper-supplying tray.
In a conventional printing apparatus including the above-mentioned printing apparatuses, use of a plurality of users is not considered as to a control of paper-supplying trays. Accordingly, even if one user is printing by using a particular paper-supplying tray at a fixed mode, the particular paper-supplying tray can be used by other users when they assign a link-tray mode. As a result, if the one user puts special recording papers in the paper-supplying tray, a printing operation of the other users may be performed with the special recording papers which the other users do not expect. Additionally, if the one user has put a predetermined number of recording papers in the particular paper-supplying tray, the recording papers may be used by the other users, and thus the one user cannot control the number of recording papers left in the particular paper-supplying tray which the one user is using.